Changes in MySQL 5.6.15 (2013-12-03, General Availability)

A known limitation of this release:

Note

If you have InnoDB tables with full-text
search indexes and you are upgrading from MySQL 5.6.10 to a
MySQL version up to and including MySQL 5.6.18, the server
will fail to start after the upgrade (Bug#72079). This bug is
fixed in MySQL 5.6.19. As a workaround, remove full-text
search indexes prior to upgrading and rebuild full-text search
indexes after the upgrade is completed.

Packaging Notes

Previously, MySQL Server distributions included the MySQL
Reference Manual in Info format (the Docs/mysql.info file).
Because the license for the manual restricts redistribution, its
inclusion in Community packages caused problems for downstream
redistributors, such as those who create Linux distributions.
Community distributions of MySQL Server no longer include the
mysql.info file, to make the repackaging and redistribution
process easier (for example, the source tarball and its checksum
can be used directly). This change applies to all source and
binary Community packaging formats. Commercial (Enterprise)
distributions are unchanged.

For those who wish to continue using the MySQL Reference Manual
in Info format, we have made it available at
https://dev.mysql.com/doc/.

Functionality Added or Changed

Incompatible Change:
Several statement instruments in the
setup_instruments table are used by
the Performance Schema during the early stages of statement
classification before the exact statement type is known. These
instruments were renamed to more clearly reflect their
“abstract” nature:

Old Instrument Name

New Instrument Name

statement/com/

statement/abstract/new_packet

statement/com/Query

statement/abstract/Query

statement/rpl/relay_log

statement/abstract/relay_log

In addition, statistics for abstract instruments are no longer
collected in the following tables, because no such instrument is
ever used as the final classification for a statement:

Applications that refer to the old instrument names must be
updated with the new names. For more information about the use
of abstract instruments in statement classification, see
Performance Schema Statement Event Tables.
(Bug #16750433, Bug #17271055)

The Performance Schema now instruments the read/write lock
Delegate::lock, which is used for the
following classes:

A new CMake option,
WITH_ASAN, permits enabling
AddressSanitizer for compilers that support it.
(Bug #17435338)

The hash function used for metadata locking was modified to
reduce overhead.
(Bug #68487, Bug #16396598)

Bugs Fixed

InnoDB; Replication:
The InnoDBmecached plugin
would update a record before inserting to the binary log, which
would cause slave server replication to stop. The insert should
occur before the update.
(Bug #17358875)

InnoDB:
A regression introduced by the fix for Bug#17371537 resulted a
memory leak for memcached insert operations.
(Bug #17738935)

References: See also: Bug #17371537.

InnoDB:
Fault-tolerant code found in the log apply code for
InnoDBALTER TABLE ... IN
PLACE could result in data corruption.
(Bug #17625063, Bug #17512497)

InnoDB:
The trx->error_key_num field was not
initialized in the error injection code found in
storage/innobase/handler/handler0alter.cc.
The error_key_num field is usually 0 but can
be a non zero value if the memory buffer of a DDL transaction
object is reused.
(Bug #17624926)

InnoDB:
An excessive amount of memory would be consumed when querying
INFORMATION_SCHEMA.INNODB_FT_INDEX_TABLE.
The problem would occur for very large full-text search indexes.
(Bug #17483582, Bug #70329)

InnoDB:
Running SHOW ENGINE
INNODB STATUS on one connection thread and killing
that thread by running a
KILL CONNECTION
statement from a different connection thread would result in a
severe error.
(Bug #17474166)

InnoDB:
In debug builds, test case failures would occur due to
ibuf_contract_ext performing merges and
dict_stats_update returning evicted pages
back into the buffer pool while
ibuf_change_buffering_debug is enabled.
(Bug #17446090)

InnoDB:
Setting the O_DIRECT flag on a file on
tmpfs on some operating systems would result
in an error printed to the error log. Creating multiple
temporary tables on tmpfs would cause the
error to be printed repeatedly. The error message has been
changed to a warning that is only printed once when running
CREATE TABLE multiple times.
(Bug #17441867)

InnoDB:InnoDB failed to return an error when
attempting to run a query after discarding the tablespace.
(Bug #17431533)

InnoDB:
A severe error would occur after discarding a tablespace.
(Bug #17430207)

InnoDB:
The
information_schema.innodb_metricsindex_merge counter was not incremented in
btr0btr.cc. This patch also introduces new
counters (index_page_reorg_attempts,
index_page_reorg_successful and
index_page_discards) and renames the
index_merges counter to
“index_page_merge_attempts” to
distinguish it from the
index_page_merge_successful counter.
(Bug #17409657, Bug #70241)

InnoDB:
During a TRUNCATE TABLE
operation, InnoDB: Trying to TRUNCATE a missing index
of table ... warnings would be printed to the error
log. These warnings should not be printed when the index is a
full-text search (FTS) index.
(Bug #17402002, Bug #70226)

References: See also: Bug #12429565.

InnoDB:
During parallel full-text search (FTS) index creation, a scanner
thread reads in documents and passes them to the tokenizer. The
tokenizer frees documents from memory when tokenization is
complete. When tokenizing documents with a large amount of text,
the tokenizer thread would not keep pace with the scanner
thread. As a result, memory would not be freed fast enough and
the “tokenization pending list” would grow in size.
(Bug #17384979)

InnoDB:trx_create and trx_free
would be called for every memcachedget request.
(Bug #17371537, Bug #70172)

InnoDB:
A full-text search (FTS) BOOLEAN MODE query
with an invalid character in the query string could result in a
memory access violation failure.
(Bug #17350055)

InnoDB:
Full-text index creation on a large table failed due to
insufficient temporary table space and result in a misleading
“incorrect key file” error.
(Bug #17339606)

InnoDB:
In btr_validate_level there are checks to
ensure that all B-tree pages are marked when allocated. The
checks failed on the change buffer because the allocation of
change buffer pages is handled differently than other B-tree
pages.
(Bug #16884217)

InnoDB:
The hardcoded size for the srv_max_n_threads
variable was insufficient. The variable setting is now
configured based on the maximum number of connection threads and
InnoDB background threads.
(Bug #16884077)

InnoDB:
A SELECT COUNT(*) query would take a long
time to complete when run concurrently with a
LOAD DATA operation. The
mtr_memo_contains function, which determines
if an object is part of a memo in a mini transaction, contained
a nested loop that caused the query to run slowly.
(Bug #16764240, Bug #69141)

InnoDB:
When the change buffer is enabled, InnoDB
failed to write a transaction log record when merging a record
from the insert buffer to a secondary index page if the insert
was performed as an “update-in-place”.
(Bug #16752251, Bug #69122)

InnoDB:
Due to a regression in MySQL 5.6, creating or dropping tables
with innodb_force_recovery set
to 3
(SRV_FORCE_NO_TRX_UNDO) failed. Additionally,
this bug fix includes a code modification that sets
InnoDB to read-only when
innodb_force_recovery is set to
a value greater than 3
(SRV_FORCE_NO_TRX_UNDO).
(Bug #16631778, Bug #69892)

InnoDB:
An InnoDBmemcached
configuration error message contained an incorrect file name.
The error message stated, Please create config table
containers in database innodb_memcache by running
innodb_config.sql. error 31. The correct file name
is innodb_memcached_config.sql. Also, the
“error 31” portion of the error message has been
translated to its text equivalent, which is “Table not
found”.
(Bug #16498810, Bug #68684)

InnoDB:
In mutex_spin_wait(), the
sync_array_reserve_cell function could fail
to find an empty slot on systems with sync wait arrays that are
small in size, resulting in an error.
(Bug #16245498)

InnoDB:
Full-text search (FTS) index savepoint information would not be
set resulting in a severe error when attempting to rollback to
the savepoint.
(Bug #14639605, Bug #17456092)

InnoDB:
When index_read_map is called for an exact
search and fails to return a record due to non-matching search
criteria, the cursor would be positioned on the next record
after the searched key. A subsequent call to index_next
would return the next record instead of returning the
previous non-matching row, thereby skipping a record.
(Bug #14621190, Bug #15965874, Bug #17314241, Bug #70038, Bug #17413093, Bug #12860669, Bug #60220, Bug #17565888)

InnoDB:
An implicit rollback caused the server to halt when restarting
with an innodb_force_recovery
value of 3 or greater. This bug was addressed by the combination
of fixes for Bug #16310467 and Bug #17253499.
(Bug #14178835)

References: See also: Bug #16310467, Bug #17253499.

InnoDB:
Converting a table with a large number of columns from
MyISAM to
InnoDB would cause an assertion due
to insufficient log buffer space. Instead of asserting,
InnoDB now attempts to increase log buffer
size automatically if the redo log size is too large.
(Bug #11758196, Bug #50366)

Partitioning:
The storage engine was set incorrectly during a rebuild of a
partition; the table storage engine was ignored and the default
storage engine used instead. Thus, in MySQL 5.1, it was possible
for REBUILD PARTITION to change the partition
storage engine from InnoDB to
MyISAM, and for the reverse
(rebuilding partitions of MyISAM tables
causing the partitions to use InnoDB) to
occurin MySQL 5.5 and later. Now, when rebuilding partitions,
the storage engine actually used by the table is checked and
used by the handler for the rebuild operation, so that the
partition storage engine is not inadvertently changed.
(Bug #17559867)

Partitioning:
After disabling the parent table's indexes with
ALTER TABLE ...
DISABLE KEYS, rebuilding any of its partitions enabled
the indexes on those partitions, leading
MyISAM to fail with an error when
the optimizer tried to use one of the affected indexes.

Now in such cases, we check for disabled indexes on the table
before rebuilding any of its partitions. If the indexes have
been disabled, then we disable them on the partition following
the rebuild.
(Bug #16051817)

Replication:
A replication master did not handle correctly the disabling of
the semisync plugin on the master and the slave, with a
subsequent stopping of the slave.
(Bug #17460821, Bug #70349)

Replication:
The final argument in the SET clause of a
LOAD DATA ...
SET statement was repeated in the binary log.
(Bug #17429677, Bug #70277)

Replication:
When an error encountered by the dump thread while reading
events from the active binary log file was a temporary error, so
that the dump thread tried to read the event, it was possible
for the dump thread to seek the wrong position, which could
cause one or more events to be resent. To prevent this, the
thread's position is obtained after each correct read of an
event.

In addition, with this fix, only binary logs that are not closed
normally are marked as possibly being corrupted.

Finally, two warnings are added; these are now returned when a
dump thread encounters a temporary error.
(Bug #17402313)

Replication:
Setting
rpl_semi_sync_master_enabled
while the master was waiting for a reply from the slave could in
some cases cause the master to fail.
(Bug #17327454, Bug #70045)

Replication:
When stopping the I/O thread, it was possible with a very large
transaction (equivalent to a binary log size greater than 100MB)
that the thread did not receive the transaction to the end. When
reconnecting with MASTER_AUTO_POSITION=1 it
then tried to fetch changes from the next transaction, which
could lead to loss of the incomplete transaction and its data.
(Bug #17280176, Bug #69943)

Replication:
The value of LAST_INSERT_ID() was
not correctly replicated when filtering rules were used on the
slave.
(Bug #17234370, Bug #69861)

Replication:
An internal function used for storing GTID values could
sometimes try to handle them as strings of the wrong length.
(Bug #17032712, Bug #69618)

Replication:
During row-based replication with
binlog_row_image set to
MINIMAL, updating only some columns of a
table having 9 or more columns caused
mysqlbinlog to fail when it was used with the
--verbose option.
(Bug #16960133)

Replication:
Issuing a GRANT statement with
invalid parameters caused the master to write
LOST_EVENTS events into its binary logs,
causing replication to stop. Now such cases, if one or more
grants or revocations of privileges are successful, an incident
is written to the log; otherwise, only a warning is logged.
(Bug #16629195, Bug #68892)

libmysqlclient version 18 files were removed
from MySQL-shared-compat RPM packages to
avoid a conflict between the MySQL-shared and
MySQL-shared-compat RPM packages.
(Bug #17749617)

Enabling Index Merge optimizer switches and setting a small
sort_buffer_size value could
lead to a server exit.
(Bug #17617945)

Some license and documentation files were missing from Windows
MSI packages.
(Bug #17584523)

Semijoin materialization strategy was not used for
VARCHAR columns longer than 512 bytes,
resulting in use of a less-efficient strategy and worse query
performance. (The limit in characters rather than bytes depends
on the column character set; 170 characters for
utf8, for example.)
(Bug #17566396)

Using MySQL Installer to install MySQL on Windows, then using
Uninstall a Program in the Control Panel to uninstall MySQL,
resulted in the MySQL service entry not being removed.
(Bug #17550741)

Selecting from the
session_connect_attrs Performance
Schema table under high load could cause a server exit.
(Bug #17542370)

The mysql_options() C API
function could leak memory if called more than once with the
MYSQL_SET_CLIENT_IP option.
(Bug #17297012)

The CONV() function could call
abs(INT_MIN), which is undefined, and cause a
server exit.
(Bug #17296644)

An error array in the SSL code was missing a comma, leading to
implicit concatenation of adjacent messages and a resulting
off-by-one error in the relationship between error numbers and
messages.
(Bug #17294150)

GRANT without an
IDENTIFIED BY clause resulted in an error
even for existing users.
(Bug #16938568)

GROUP_CONCAT() with an invalid
separator could cause a server exit.
(Bug #16870783)

An internal InnoDB string routine could write
past the end of a buffer.
(Bug #16765410)

For uninstall operations, the MySQL Server MSI installer failed
to remove some files if the server was running. This could lead
to problems for a subsequent installation of a lower MySQL
version: The installer reported a successful operation but not
some of the files from the original installation were not
replaced by their lower-versioned counterparts.
(Bug #16685125)

GIS intersection-related code was missing a return value check,
leading to a loop in nondebug builds and a raised assertion in
debug builds.
(Bug #16659166)

Using the binary client/server protocol, the second execution of
a prepared statement for a query with parameters in the
LIMIT clause raised an assertion.
(Bug #16346241)

For upgrades using the Windows MSI package installer, the
upgrade dialog message was missing the “from”
version.
(Bug #16053094)

Very long database names in queries could cause the server to
exit.
(Bug #15912213, Bug #16900358)

Standalone Windows MSI packages did not have the
ALLUSERS property set. They now set
ALLUSERS=1. For earlier MSI packages in this
MySQL series, a workaround is to use the following command:

C:\> msiexec /i msi_installer_name ALLUSERS=1

(Bug #14647206)

Recursion by functions called as arguments to XPath expressions
was not handled correctly, sometimes causing such expressions to
fail.
(Bug #14040071)

In some cases, range conditions over indexes defined on column
prefixes returned incomplete result sets. (For example,
SELECT ... WHERE 'abcdef1' <
col_name AND
col_name < 'abcdef9',
where the index on col_name indexed
only the first 6 characters.)
(Bug #70341, Bug #17458273)

If asked to upgrade a server that was running without
InnoDB enabled,
mysql_upgrade issued complaints about
InnoDB tables not existing (tables that will
not exist unless InnoDB is available).
(Bug #70152, Bug #17361912)

With the thread pool plugin enabled, the
PROCESSLIST_USER and
PROCESSLIST_HOST columns of the
threads Performance Schema table
were always NULL for client sessions. Also,
for the main thread, those columns were not
NULL but set to a user account.

Note

As part of the bug fix implementation, Performance Schema
instrumentation for the thread pool plugin was changed to use
thread_pool, not sql.

Some INSERT INTO ... SELECT ... FROM
statements were slow unless the
tmp_table_size and
max_heap_table_size system
variables were set large enough to permit the temporary table
used for query processing to be stored in the
MEMORY storage engine.
(Bug #69368, Bug #16894092)

Some possible cases of memory use after being freed were fixed.
Thanks to Jan Staněk for the patch.
(Bug #68918, Bug #16725945)

For queries of the form UPDATE ... WHERE
unique_key ORDER BY ... LIMIT
..., incorrect rows could be updated. Unique keys
permit multiple NULL values, but the
optimizer did not always consider all of them.
(Bug #68656, Bug #16482467)

For an ALTER TABLE statement that
renamed or changed the default value of a
BINARY column, the alteration was
done using a table copy and not in place.
(Bug #67141, Bug #14735373, Bug #69580, Bug #17024290)

The server uses the ethernet hardware address for UUID
generation, but made assumptions about the names of ethernet
devices rather than querying the system for their names. Thanks
to Honza Horak for the patch.
(Bug #63055, Bug #13548252)

Host names in grant tables are stored in lowercase, but
mysql_install_db could fail to observe this
convention, leading to accounts that could not be dropped with
DROP USER.
(Bug #62255, Bug #12917164, Bug #62254, Bug #12917151)

Killing a query that is performing a filesort
operation resulted in an
ER_SERVER_SHUTDOWN (Server
shutdown in progess) error.
(Bug #18256, Bug #11745656)